This application relates to a debris filter incorporated into a reverse facing J-Tube for supplying motor and air bearing cooling air.
In aircraft, one item that operates to supply cooling air on is a ram air fan. The ram air fan is driven by an electrical motor, and acts as the motive force to move air across heat exchangers that expel heat from the aircraft to the outside air environment. The ram air fan is located after the heat exchanger, and pulls air through an inlet header and across heat exchangers, and through an outlet header, downstream of the heat exchangers to an inlet for the fan. The fan then exhausts the air through a ram outlet door on the aircraft.
A tube is placed within the inlet header, and captures a portion of the air which is ported through ducts around the heat exchangers to the ram air fan motor, and its bearings, to cool the motor and bearings.
In the prior art, the tube has sometimes allowed the ingestion of insects, paper, or other types of debris. This debris has sometimes blocked slots within the motor, which is undesirable.